Firearm,particularly light antitank weapon



Jan. 20, 1970 w. WALTHER 3,490,330

FIREARM, PARTICULARLY LI GHT ANTITANK WEAPON Filed March 8, 1968 2Sheets-Sheet 1 Fig. 7 J I Fig.2 I

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United States Patent I 33,228 Int. Cl. F41f 3/02, 15/00 U.S. Cl. 891.7 7Claims ABSTRACT OF THE DISCLOSURE A firearm, particularly a lightantitank weapon in which the recoil impulse upon firing a projectile isat least partially intercepted by a counter-thrust drive device arrangedat the rear end of the gun barrel. The gun barrel is slidably mounted ina tubular guide provided with a shoulder support, handles and a triggeron one of the handles. Within the gun barrel a slidable pistondriven bya propellant chargehas mounted thereon the projectile. When theprojectile leaves the barrel, the piston is intercepted by anintercepter device at the muzzle end of the barrel. The gun barrel thenmoves rearwardly in the guide and is arrested by the counter-thrustdrive device and may even be completely discharged from the rear end ofthe tubular guide.

The invention relates to a weapon provided with a counter-thrustdrive-system for at least partial intercept of the recoil impulsestaking effect on the barrel upon firing of a projectile, particularly alight shoulder-weapon for defense against tanks.

Firearms are already known, in which the recoil impulse taking eifect onthe gun barrel upon firing of a projectile is partially or entirelyintercepted. In the case of weapons of this type constructed aslight-guns free from recoil, there is disposed on the rear end of thegunbarrel a nozzle, through which upon firing the projectile aredischarged propellent charge gases, and an impulse directed opposite tothe recoil impulse and substantially equally great, is produced. Thedisadvantage of such weapons consists therein, that even upon theslightest deviations of the nozzle axis from the gun-barrel axis, whichis practically not to be prevented, the thrust power of the nozzle drivemechanism possesses a force component directed perpendicularly to thebarrel axis. As a result thereof, torsional moments act on the barrel,which lead to angular distortions of the weapon with respect to thedesired firing direction, while the projectile passes through thegun-barrel. Misfirings result therefrom.

Along the line of the above described lightweight guns, there have alsobeen produced previously light shoulderweapons, particularly antitankweapons. *In addition to the insuflicient accuracy of fire, a greatdisadvantage of these weapons is the great acoustic effect on account ofthe muzzle blast during the discharge of the projectile from the barreland the ignition blast of the intercept drive-mechanism substantiallycoinciding therewith. As a result, injuries to the hearing may occurupon firing.

A weapon free from recoil is also known, in which, in a gun barrel openon both ends, a liner or inner tube closed on 'one side islongitudinally slidably mounted. This liner receives the projectile andthe propellent charge. Upon firing of a projectile, with this weapon, onaccount of the recoil impulse taking elfect on the liner or inner tube,the liner or inner tube is ejected rearwardly from the gun-barrel whichis open at both ends. Although the liner or inner tube possesses agreater bulk than the projectile, behind a projectile of this typeconsiderable 3,490,330 Patented Jan. 20, 1970 safety areas are necessaryinto which the liner or inner tube is ejected. Such great safety areas,however, are solely available in exceptional cases. Insofar, the gundescribed above is adjustable solely to a limited extent and has beenintended also especially as a gun for aircraft.

The object of the invention consists in the furnishing of a firearm,preferably a light shoulder-weapon for defense against tanks, in whichthe recoil impulse upon firing of'a projectile is at least partiallyintercepted by means of a counter-thrust drive-device whereby noacoustic effects occur upon firing, which could lead to hearing injuriesof the gunner. Furthermore, upon firing of a projectile, the safety arearequired behind the weapon shouldbe as small as possible.

Starting with a firearm, particularly a light shoulderwepaon, with agun-barrel receiving a projectile and a propellent charge, the formerbeing provided with a counter-thrust drive mechanism for at least apartial intercept of the recoil impulses taking effect on the gun barrelupon firing of the projectile and a guide constructed preferably as ashoulder support, on which trigger devices are arranged for the releaseof a propellent charge and stop means releasable upon firing of theprojectile, and in which said guide is positioned to be slidable inlongitudinal direction, the solution of the stated problem consists inthe arrangement of a piston serving as projectile-drive-base, which ispositioned longitudinally slidably in the gun-barrel and is connectedtightly with the projectile, however, still releasable upon discharge,further characterized therein, that in the gun barrel muzzle apiston-intercept-device is fixedly disposed for intercepting the pistonupon forward motion.

Upon discharge of the projectile from the gun-barrel, with the weapon ofthe present invention, no muzzle sound of the ordinary type occurs, asthe piston driven forward on account of the gas pressure stress in thegun barrel is intercepted by means of the intercept device in thegun-barrel-muzzle and closes the same substantially gastight.

In a suitable manner, the piston may be held tight in the gun-barrel bymeans of a holding means, whose holding power is released solely underthe action of a predetermined piston force. The holding means may be atension rod connected with the end of thegun-barrel facing away from thepiston and the barrel muzzle, said tension rod being provided with asuitably dimensioned breaking point corresponding to the desiredbreaking force of the piston. In this way, a high starting accelerationof the piston and with it a great acceleration of the projectile in thegun-barrel is insured.

In particularly suitable manner, the holding means may be an ignitiontube which extends axially through the propellent charge and is fixedlyconnected with the barrel end.

In a further advantageous embodiment of the invention, thecounter-thrust-drive-mechanism may, in a manner known 'per se, be anozzle drive mechanism operated by the combustion gases of thepropellent charge.

Since after the discharge of the projectile from the gunbarreL'thebarrel muzzle is closed tightly by means of the piston guided in thebarrel and therefore .no drive gases can escape from the barrel muzzle,the gun barrel after the firing of a projectile acts asgas-pressure-storage member and the drive gases then first partiallyreleased are available for the supply to thecounter-thrust-drivemechanism. Insofar, with the firearm of theinvention, solely one propellent charge is required, and thedrivemechanism-thrust may be held small in comparison with the forceowing to recoil impulse of the projectile, as the operation of theco-unter-thrust-drive-mechanism lasts very long in comparison with thetime in which the projectile passes through the gun-barrel. Any possibledisturbing forces, which may occur in view of inaccurate alignment ofthe longitudinal axis of the gun-barrel with the longitudinal axis ofthe counter-thrust-drive-mechanism, are accordingly small and lead to noappreciable angular displacement of the gun-barrel.

Preferably the counter-thrust-drive-mechanism may have a gas-pressuringchannel which discharges at such a point in the gun-barrel, that theimpacting of the drivemechanism with gas pressure takes place only thenwhen the piston has returned to a partial distanc into the gunbarrelafter the ignition of the propellent charge. For example, the gaspressure impact channel may discharge in the area in the gun-barrel,which upon a non-fired propellent charge is uncovered by a shaft of thepiston.

The advantage of this feature lies therein, that upon break off of thepiston, namely upon the beginning of movement of the projectile, nodriving mechanism output and accordingly no laterally disturbing forcesare present. Only after the piston has covered a pre-determined distancealong the gun-barrel, is the counter-thrust drive mechanism impacted bygas pressure and a thrust force directed oppositely to the recoilimpulse and which at the beginning of the actuation of the drivemechanism is still small, is produced.

With a particularly suitable embodiment, the counterthr-ust drivemechanism comprises a ring of nozzles which concentrically surrounds thegun-barrel, and whose nozzles are disposed preferably at equal angularspacings from one another in a manner known per se, so that theresulting thrust force acts on the center of gravity of the gunbarrel.The axes of the driving mechanism-nozzles may in this connection bedirected inclined outwardly and from mantle lines of a cone imagined toopen towards the firing direction, and the longitudinal axis coincideswith the longitudinal axis of the gun-barrel.

The arrangement of the nozzles may with advantage be selected in such amanner that the resulting thrust force acts on the center of gravity ofthe gun-barrel. In this manner it is insured that even upon loss of athrustnozzle, no torsional moments take effect on the gunbarrel.

In the propellent charge space which is disposed between the pistonguided in the gun-barrel and the rear barrel-end, there may be disposedadjacent to the main propellent charge an additional propellent chargemade of slow-burning propellent substances. On account of the slowcombustion of this propellent substance, the additional propellentcharge furnishes no noteworthy addition to the firing of the projectile,but serves for supplying gas to the counter-thrust drive mechanism for alonger period of time. The additional propellent charge may also consistof a propellent substance having a great ignition inertia, or it may beshielded with respect to the main propellent charge by a covering whichis destructible under the influence of heat upon combustion of the mainpropellent charge. Suitably the additional propellent charge consists ofa solid-rocket-composition disposed at the rearward end of thepropellent charge space.

A further substantial feature of the invention consists therein, thatthe piston which serves as a projectile drivebase possesses adeformation section with great workrecelvlng capacities, which upon theintercept operation enters into the piston intercept device and isdeformed there, whereby a conversion of the kinectic energy inherent tothe piston into deformation energy takes place. Suitably the deformingsection of the piston lies in front of the piston base, on which theprojectile is releasably mounted.

The piston intercept device may comprise an insert piece, whichconcially tapers toward the gun-barrel-muzzle, said insert piece havingon the piston-entry side the same or a somewhat larger diameter than thepiston.

In the following, the invention is described more in detail withreference to an embodiment by way of example which is shown partiallydiagrammatically in the appended drawings.

In the drawings:

FIG. 1 illustrates diagrammatically a weapon of the invention inlongitudinal section;

FIG. 2 illustrates diagrammatically and in section the same weaponshortly after the ignition of the propellent charge;

FIG. 3 illustrates the weapon after the firing;

FIG. 4 is a side view of the weapon with a portion in section;

FIG. 5 illustrates the piston intercept device with intercepted piston,partly in section.

Referring to the drawings, the weapon essentially consists of agun-barrel 1 and a gun-barrel guide 2 constructed as shoulder-support.The gun-barrel is slidably guided with anti-friction property indirection of its longitudinal axis in the guide 2. The guide 2 isprovided with means, not shown, for arresting of the gun-barrel whichmeans only upon firing of the weapon are released and thereby releasethe gun-barrel. The arrangement is made in such a manner that thegun-barrel may be shifted from the position shown in FIG. 1 upon firingsolely rearwardly--namely opposite to the firing direction-and if needbe may completely leave its guide.

The rearward end 3 of the gun-barrel 2 is closed by a rear wall 4.Within the gun-barrel is disposed a piston 5, which before the firing isheld in its position by means of a holding device 6 provided with abreaking point and upon firing is movable along the barrel to thebarrelmuzzle 7. In the barrel muzzle is disposed a piston interceptdevice 8 described hereinafter more in detail. The piston 5 is providedon its end facing the gun-barrel muzzle with a receiver for theprojectile 9. Between the piston 5 and the end of the gun-barrel closedby the rear wall 4 is disposed the propellent charge chamber 10. At therearward end 3 of the gun-barrel 2 is furthermore disposed acounter-thrust drive 11, whose nozzles lie symmetrically to the axis ofthe counter-thrust drive and is directed toward the rear, namely,opposite to the direction of firing. The high pressure sides of thedrive mechanism nozzles discharge into such a point in the gun-barrel,that the nozzles are provided only then with gas pressure, when afterthe ignition of the propellant charge, the piston 5 carrying theprojectile 9 has traveled a pre-determined distance. This is shown inFIG. 2.

The barrel guide 2 surrounds the gun barrel 1 substantiallyconcentrically and extends over a part of the length of the gun barrel.The barrel guide is provided with a shoulder-support 12 as well as twohandles 13, 14. On the handle 13 is disposed a trigger device 15.

Details of the weapon construction are shown in FIG. 4. The gun barrel 1consists of a front cylindrical barrel section 20 and the readward end3. The cylindrical barrel section 20 and the end 3 of the gun barrel arethreadedly connected with each other by means of a screw thread 21. Onthe front end of the screw thread, the gun barrel is provided withflange 22 projecting radially from the gun barrel, said flange engagingthe rear end the barrel guide 2 and preventing a further forwardmovement of the gun barrel 1 in the barrel guide 2. The hollow space ofthe gun barrel lying behind the piston 5 in FIG. 4 serves as apropellant charge chamber. In the illustrated embodiment, the propellentcharge consists of a solid rocket composition 23 and a powder charge 24.From the rear wall 4 of the gun barrel extends the holding device forthe piston 5 constructed as ignition tube 6 in firing direction alongthe gun barrel axis. The piston 5 and the ignition tube 6 are securedtogether by means of a screw thread 25. In the vicinity of the screwthread 25, the ignition tube 6 possesses a breaking point 26. Inaddition, the ignition tube 6 is screwed in a manner not of greaterinterest here, into the rear wall 4 of the end 3 of the gun barrel. Theignition tube 6 is provided in the area of the propellent charge spacewith a number of bores 27, which connect its inner chamber with thepropellent charge chamber. Within the gun barrel is located a primercharge 29 enclosed by a plastic casing 28, in which primer charge anelectric bridge-igniter 30 is embedded. The bridge-igniter 30 is inconnection, in a manner not of interest here, through electricconductors 31 with an ignition contact actuatable by the trigger device15.

For insuring a smooth guidance of the projectile through the projectilepassage in the gun-barrel, the piston is provided with a piston wall 33of considerable length. The forward end 34 of the piston possesses areceiver 35 for the projectile 9. For improving the gas seal, the pistonis provided with piston rings 36, 37.

In the area of the end of the gun-barrel in which the piston 5 held inits position by means of the ignition tube 6, is arranged, before thefiring, the counter-thrust drive mechanism 11 in the form of an annularseries of thrust nozzles 40. On the high pressure side, the nozzles areprovided with a gas compacting channel 41, which is covevered by pistonwall 33. This channel 41 is first uncovered for gas pressure admissionafter, as a result of ignition of the propellent charge 24, the piston 5has been moved from its starting position apredetermined distanceforwardly. Thereafter, the thrust nozzles 40 of the counterthrust drivemechanism 11 are pressured by the propellent charge gases and exert athrust force directed against the recoil impulse upon firing of theweapon. By means of a suitable dimensioning of: the breaking point 26,the break-off force of the piston may be adjusted within wide limits, insuch manner, that the piston upon firing of the weapon receives a highstarting acceleration.

The propellent charge 24 consists preferably of rapidly burning powder.When upon firing of the weapon, the piston moves toward the gun-barrelmuzzle, the tension release of the gas pressure in the gun-barreloccasioned thereby causes a gradual decline in the power of thecounter-thrust drive mechanism. In order to maintain the power of thecounter-thrust drive mechanism for a longer period of time, there isdisposed behind the propellent charge 24 another propellent charge 23preferably consisting of a slow-burning propellent substance. Betweenthe two propellent charges 23, 24 is located a foil 42, which undereffect of temperature during the burning of the charge 24 is destroyedand delays the ignition of the propellent charge 23.

On the gun-barrel muzzle 7 is disposed a piston intercept device 8. Thepiston intercept device comprises an insert piece secured by means of ascrew-thread 45 in the gun-barrel, and has an inner wall surfacetapering conically towards the gun-barrel-muzzle. This conical insertpiece receives the piston driven by the gas-pressure along thegun-barrel and undergoes thereby a deformation dissipating its kineticenergy. After the interception of the piston at the barrel muzzle, thegun-barrel is closed and the combustion gases still contained in thebarrel are now completely available for the operation of thecounterthrust-drive mechanism. On account of the great decelerationoccurring upon the entry of the piston in the piston intercept device,the projectile 9 is released due to its inertia from theprojectile-receiver 35 in the piston bottom and moves then on aballistic trajectory. 1

As was already indicated above, the gun-barrel-guide 2 is provided withmeans for arresting the gun-barrel 1 which are released upon firing. Inthis manner, the gunbarrel can perform during the firing a returnmovement, withoutapart from the low frictional forces-causing the recoilforces to effect the gun-barrel-guidance and thereby theshoulder-support 12. FIGS. 2 and 3 show the recoil of the gun-barrelduring the firing of the weapon. FIG. 2 shows the commencement of themovement of the piston 5. The gun-barrel recoil movement amounts to Z1.In this position, the counter-thrust drive mechanism 11 is fulloperative. The thrust force is, however, calculated that only a part ofthe recoil impulse is absorbed. FIG. 3 shows the gun-barrel-recoil atthat moment, at which the piston has entered the piston-intercept deviceon the gun-barrel muzzle, and the projectile has been released from thepiston bottom. The projectile therefore has entered on a ballistictrajectory. After the escape of the projectile from the piston, thegun-barrel continues its return movement and depending upon the designof the counter-thrust drive mechanism leaves the gun-barrel guideentirely or is arrested and on account of the continued drive mechanismthrust is conveyed back to its starting position. Preferably thecounter-thrustdrive mechanism is so designed that the gun-barrel leavesthe barrel guide towards the back and in the area of a predeterminedsafety path drops to the floor or ground behind the gun.

I claim:

1. Firearm, particularly light shoulder weapon for antitank defense,comprising a gun barrel accommodating a projectile and a propellentcharge, a guide sleeve for said gun barrel in the form of a shouldersupport in which said gun barrel is longitudinally slidable upon releaseof latch means by firing of a shot, trigger means on said guide sleeveconnected with means for setting off said propellent charge, pistonmeans slidably mounted in said gun barrel and serving as drive base forsaid projectile, connection means on said piston means rigidly holdingsaid projectile until released after the firing of a shot, counterthrust means including space at the rear of said gun barrel for anauxiliary charge of a propellent with high ignition inertia for at leastpartial off-setting of the recoil impulse at the firing of a shot, andpiston intercept means secured to the muzzle end of said gun barrel tointercept the forward movement of said piston means.

2. Firearm according to claim 1, in which said piston intercept meanscomprises an insert piece tapering conically inwardly towards thegun-barrel muzzle, the piston receiving end of said insert piece havinga somewhat greater diameter than the piston means.

3. Firearm according to claim 1, including a breakable ignition tubesecured to said piston means and to the rear end of said gun barrel andextending through said propellent charge.

4. Firearm according to claim 1, in which said auxiliary chargecomprises a slow-burning propellent.

5. Firearm according to claim 1, in which said piston means includes adeformation section with great energy absorption capacity, saiddeformation section entering said piston intercept means at the firingof a shot and being deformed thereby.

6. Firearm according to claim 5, in which said deformation section isdisposed in front of the portion of said pistcin means directly servingas drive base for the projecti e.

7. A light antitank shoulder-weapon, comprising in combination a'gunbarrel accommodating a projectile and propellent charges,

a guide sleeve for said gun barrel in the form of a shoulder support inwhich said gun barrel is longitudinally slidable upon release of latchmeans through firing of a shot,

ignition means in said gun barrel, trigger means mounted on said guidesleeve and connected with said ignition means,

piston means slidably mounted in said gun barrel and having a portionwhich serves as a drive base for said projectile,

holding means on said piston means for releasably maintaining saidprojectile in engagement with said drive base on the piston means,

counter thrust means in the rear portion of said gun barrel to at leastpartially offset the recoil impulse at the firing of a shot, saidcounter thrust means including a propellent chamber rearwardly of saidpiston means to accommodate a main propellent charge and an auxiliarypropellent charge which References Cited UNITED STATES PATENTS 2/1890Reynolds 891 X 3/1950 Garrett 891 X 2,834,255 5/1958 Musser 891.7063,255,668 6/1966 Vilbajo 891.705 3,338,133 8/1967 Grandy 89--1.703

FOREIGN PATENTS 578,595 6/ 1959 Canada. 590,268 7/1947 Great Britain.

SAMUEL W. ENGLE, Primary Examiner US. Cl. X.R.

